The instant invention relates to value metering systems. More particularly, the instant invention is directed to a postage metering system that ensures that the currency accounted for and the currency printed as part of a postage indicium by the postage metering system are consistent with each other.
Postage meters of both the electronic and mechanical variety have conventionally had all of the accounting and printing control structure contained in a secure single housing in order to protect against tampering. Recently, however, advances in microelectronics, digital printing, and encryption techniques have led to the design of modular postage metering systems where the postage accounting and printhead modules are designed to be easily removed at a customer's site. In these newer systems, the postage accounting vault may a portable device, such as a smart card, which can be removably inserted into a base module containing the metering system interface controls and a removable printhead module. The portable device is designed to be carried by a user for insertion into the base module whenever postage is to be dispensed and charged to that portable device. The benefits of the portable device are that multiple users can access a single base module. Alternatively, instead of individual portable devices some postage metering systems have an easily removable accounting module within the base module. The removable accounting module acts as the vault for all postage dispensed by the postage metering system in lieu of separate portable devices. However, even where a single removable accounting module is used, its easily removable design permits for its replacement in the event of, for example, a vault failure. For the purpose of this application the portable accounting devices and the removable accounting modules are collectively referred to as modular vaults.
In the modular postage metering systems described above, all of the components are easily accessible and not contained within a single secure housing. Accordingly, security is provided via encrypted communications between the various metering system modules. Moreover, it has been proposed to utilize encrypted information, which is printed together with the postage indicia for increasing security relative to fraudulently printed postage indicia. That is, the printed encrypted information on any mailpiece can be subsequently scanned and analyzed by a postal authority to determine the authenticity of the printed indicia on the selected mailpiece. Thus, while the scanning of every single mailpiece being processed may not be considered practical, random sampling of individual mailpieces would likely identify any large-scale fraudulent indicia printing operation.
The use of the above-discussed modular metering systems has provided great flexibility in postage meter system design. For example, individual accounting and printing modules can be easily replaced, if defective, without having to return the entire metering system to the postal authority. Moreover, the enhancements in encrypted security techniques have even led to the development of personal computer metering concepts where non-dedicated computer printers are used to print the postage indicia. In addition, where portable accounting devices are used, the metering system user is provided with a great deal of operational flexibility because any number of portable accounting devices can be inserted into any single base module for the purpose of printing postage. Thus, a company can have a central base module and allocate individual portable postage vaults to different departments. Since each portable vault can be controlled via software to have a postage fund limit, flexibility is provided in that individual departments can easily place postage on items to be mailed while individual accounting and postage expenses are carefully monitored in each portable vault. This same concept can also be used to locate a base module at a central location in a community, such as a convenience store. Individuals could then obtain portable vaults for use in the central base module so that postage could be applied to their mailpieces. Since the postage is prepaid for and accounted for in the individual portable vaults, the mailing of individual pieces of mail (or even a batch of mail) becomes easier for individuals without requiring them to procure or rent the entire base module.
One example of a postage metering system that uses a single removable accounting module (vault) is the E700 postage meter manufactured by Pitney Bowes Inc. The removable accounting vault accounts for all of the postage received and dispensed by the postage meter while a removable printhead module has stored therein all of the indicium graphics required for printing the postage indicium on a mailpiece. Since both the printhead module and the removable accounting vault are easily accessible, security is provided through a mutual encrypted handshake that occurs prior to the printing of the postage indicium. The handshake procedure permits the accounting vault and the printhead module to verify the authenticity of each other as approved postage metering modules. Moreover, the mutual handshake procedure is implemented in all E700 or equivalent models regardless of which country the postage meter is to be deployed. That is, postage metering systems may be deployed on a worldwide basis. Thus, the design of the postage indicium printed is subject to specification/approval by local postal authorities. While this results in the need to customize the indicium graphics for each country, the fact that a common mutual authentication handshake is used permits the easy configuration or reconfiguration of any specific postage metering system for use in any country.
It has further been proposed to have a plurality of different country indicium graphics stored in a postage metering system in order to permit the easy reconfiguration of the postage metering system between the different countries. Such a postage metering system would be useful, for example, in Europe where the Euro dollar is being introduced. That is, if the Euro dollar graphics are stored in a postage metering system currently configured to account for and print an indicium in a local currency, the conversion of that postage meter to account for Euro dollars and print a corresponding Euro dollar indicium in the future is greatly simplified.
While the modularity and commonality of postage metering designs have produced the advantages discussed above, there exists a potential security problem. That is, suppose two meters exist in a country in Europe. The first postage meter has a vault and printhead that respectively account for and print the postage indicium in the local currency. The second postage meter has been reconfigured to account for and print the indicium in Euro dollars. Also, assume for example, that due to the exchange rate, one Euro dollar is equal to 100 local currency dollars. Thus, if the printhead module of the local currency postage meter was replaced with the printhead module of the Euro dollar meter an attacker would realize a significant gain since the printed postal indicia appearing on its face to indicate one Euro dollar would only be accounted for as one local dollar.
Therefore, there is a need for a modular postage metering system that is designed for modularity, commonality and ease of reconfiguration while at the same time ensuring that currency compatibility exists between what is accounted for and what is printed.